1. Field of the Invention
The present invention relates to a probe card and a method for assembling the same and, more particularly, to a probe card for forming a micro strip line between a fixing member and terminal ends of probes via a fixing ring and the fixing member. The probe card has simple structure, low cost, and is suitable for measuring high frequency signals.
2. Description of the Prior Art
In semiconductor-manufacturing factories, when all manufacturing processes are finished, wafers generally need to take wafer testing (WAT) to check whether the electronic connection from the wafers is normal. A probe card is usually used as a measurement medium to ensure the manufacturing quality when executing the wafer test for wafers. Only are the qualified wafers sent to continue the steps of package and other final tests.
As shown in FIG. 5, the conventional probe card 9 is a printing circuit board “A” and has many probe pins “C” electronically connected with the circuit respectively. The probe card is provided with a central aperture “B”, and the plural probes “C” are connected to the peripheries of the bottom of the probe card and extending downwardly form the peripheries toward the central aperture “B” of the probe card in an inclined direction. The terminal end of each probe “C” is located under the central aperture “B” and the point of each probe and its corresponding circuit form a channel. When the wafer testing is to be executed, whether the electronic characteristics of wafers are normal can be checked only by contacting all points of the probe card to specific points on wafers and inputting measurement signals. When the measured signal frequency is getting higher and velocity is increased, the problem of impedance matching should be considered. However, known manufacturing methods for manufacturing probe cards fail to meet this need.
Recently, a high frequency probe card is designed to utilize coaxial cables to replace traditional probe cards on measurement. However, because of the large size of the coaxial cables, the probe cards using coaxial cables are difficult to be designed and manufactured within limited space in a base plate, and it is also inconvenient for operators in adjustment and measurement. Moreover, although membrane probe cards have been invented to substitute the probe cards using coaxial cables for measurement, more steps are needed in manufacturing membrane probe cards, which will elevate the cost.